The Umbra King by Jamie Applegate Hunter
he morally grey don’t want redemption. They want retribution. After the brutal murder of her twin sister, Aurora “Rory” Raven spends years forging herself into a ruthless vigilante killer. She never gave up her search for the man who killed her sister, but when she is convicted of thirteen murders and sentenced to five-hundred years in Vincula, the prison realm, she knows her sister’s death will never be avenged.
